Dedicated Bibliometrics: A More Appropriate Impact Factor for Specialty Journals?

Much can be done to improve the criteria used for comparative evaluation of scientific journals. The impact factor is an artificial number that provides an estimate of the relative importance of articles published in journals, used by investigators looking for the journal with the greatest effect in the field and by university promotion committees to assess the worth of a faculty member’s publications. The impact factor is calculated from the number of citations to articles in a journal in the previous 2 years, divided by the number of articles published in the journal during the same period. Such standard bibliometric indicators give more weight to general-interest journals compared with specialized publications, tend to underestimate clinical versus basic research, and fail to take into account marked differences in citation practices among and within fields. We were surprised, and quite pleased, to learn from the bibliometric analysis by Master et al (1) that the Journal of Pediatric Gastroenterology and Nutrition published the most articles on celiac disease in recent years. Moreover, their study shows that the research on celiac disease reported in JPGN and in the journal with the next highest number of articles on celiac disease-related research in adults was comparable in study topic, scope and design, statistical method, country of origin, number of authors, multicenter collaboration, and funding sources. This is despite significant differences in reported impact factors: in 2011, JPGN’s impact factor was 2.298, whereas the American Journal of Gastroenterology had an impact factor of 7.282. The findings in this short report suggest that a comparative analysis focused on a specific field may provide a more balanced and useful estimation of the “impact” of a journal in its area of specialization.